Airplane



Mai-ch 15, 1932.

H. A. HICKS I AIRPLANE Filed March 28, 1930 USED INVEN TOR. A 62. A MA.

A TTORNEY.

Patented Mar. 15, 1932 UNITED STATES- PATENT OFFICE HAROLD A. OFDETROIT, MICHIGAN, ASSIGNOR TO FORD MOTOR COMIPANY, OF DEABBORN,MICHIGAN, A CORPORATION OF DELAWARE AIRPLANE Application filed March 28,1930. Serial No. 439,569.

The objectof my invention is to provide an airplane having a novel typeof landing gear especially adapted to preventdamage to the plane if itshould nose over while it is land ing. Frequently airplanes, especiallythose equipped with brakes, will make a landing on soft groundand therunning resistance together with the braking resistance will offer sucha great restriction to the landing gear that the plane will tiplengthwise or nose over doing great damage. To prevent such nosing over,the landing wheels are usually placed far forwardly of the center ofgravity.

For planes not equipped with brakes there is no serious objection tosuch forward placing of the wheels, but when brakes are to be used onthe wheels it is very advantageous to place these wheels only slightlyforward of the center of gravity of the plane so that practically thefull weight of the plane will act on the brakes to thereby stop theplane in the shortest possible space.

The above type brakes are very eflicient but one serious objection isencountered in their use. This objection arises because the center ofgravity of the plane, being almost directly above the wheels, tends topivot forwardly around these wheels when the brakes are applied so thatthe nose or front end of the fuselage is forced into the ground with theconsequent da mage to the plane.

My invention relates to a landing gear having braking wheels placedsubstantially below the center of gravity of the plane so that maximumbraking efliciency may be obtained therefrom combined with a normallyinoperative nose wheel mounted beneath the front end of the fuselage anda normally operative rear wheel mounted beneath the tail portion of theplane. When the plane is taking-ofi and normally landing, the brakingwheels and the rear wheel support the weight of the plane, while whenthe brakes are fully applied the center of gravity shifts forwardly sothat the two braking wheels and the nose wheel support the weight of theplane. It

will be seen that at all times the braking wheels are disposed almostdirectly beneath the center of gravity of the plane so that veryefficient braking is always obtained.

It will be understood that there are two positions in which the planetravels on the ground, the normal horizontal position where the twocenter wheels and the rear wheel are rolling on the ground, and thenosed over position wherein the brakes are applied with the centerwheels and nose wheel rolling on the ground.

The structure forming the subject of this application consists of mylanding gear having two sets of wheels so placed in relation to thecenter of gravity of the plane that under certain conditions the planewill be supported in stable equilibrium upon each set; the one setsupporting the plane while it is standing still, in uniform motion, oraccelerated motion, and the other set supporting the plane while it isslowing down due to the application of the brakes.

\Vith these and other objects in View, my invention consists in thearrangement, construction, and combination of the various parts of myimproved device, as described in the specification, claimed in myclaims, and illustrated in the accompanying drawings, in which:

Figure 1 shows a side elevation of an airplane constructed in accordancewith this invention shown in the nosed over position with the brakesapplied, and

Figure 2 shows a front View of a portion of the airplane shown in Figure1.

Figure 3 shows a side elevation of a portion of an alternate structurehaving a nose skid in place of the nose wheel shown in Figure 1.

Referring to the accompanying drawings, I have used the referencenumeral 10 to indicate generally an airplane fuselage havinga pair ofwings 11 secured on either side there of, a rudder l2, and controlsurfaces 13. A I

pair of engine nacelles 14 extend upwardly from the top side of eachwing 11, one on each side of the fuselage 10, and a pair of motors 15are secured in each nacelle to propel the plane.

I have designated the position of the center of. gravity of the plane byacross 16 which it will be noted is near the center of the fuse-- lagebeneath the engines 15. I have provided a pair of landing wheels 17,disposed slightly forwardly of the center of gravity of the plane in itshorizontal position which are each rotatably mounted at the outer end ofstruts 18. These struts extend outwardly from the bottom portion of thefuselage to which they are pivotally secured at 23 and swing around thispivot to absorb the landing impact. A pair of compressible struts 19extend from the outer ends 'of the struts 18 upwardly and are fastenedto the under side of the wings 11 to thereby resiliently support theweight of the plane on the wheels 17. A tail wheel 20 is fastenedbeneath the rear end of the fuselage 10 which may be provided with ashock absorbing element if desired. This wheel is preferably arranged toswing around a substantially vertical axis so that the plane may bemaneuvered on the ground. I have provided a brake 22 on each of thewheels 17 which may beoperated by the pilot from within the fuselage theconventional manner.

When the plane is standing, taking-off, taxiing for position, or makinga landing without fully applying the brakes, the two wheels 17 togetherwith the tail wheel 20 support the weight thereof. The center of gravityis at this time a slight distance to the rear of the wheels 17 so thatthe plane is in stable equilibrium upon these three wheels, even thoughpractically all of the weight is carried by the wheels 17. If while theplane is landing it is necessary to fully apply the brakes, veryefficient braking is assured due to the great weight placed on thebraking wheels. However, when the brakes are applied the center ofgravity swings forwardly around the braking wheels a distance dependingupon the deceleration produced by the brakes so that as it swingsforwardly of the wheels 17 the front end of the fuselage drops towardthe ground.

I have provided a nose wheel 21' rotatably mounted beneath the forwardend of the fuselage which is in a position to roll against the groundwhen the plane is thus nosed over to thereby protect the fuselage fromdamage. As long'as the plane is decelerating sufficient to shift thecenter of gravity forwardly of the wheels 17 the plane will roll alongon the nose wheel 21 and braking wheels 17 Even while rolling in thisnosed over position near- 1y all of the planes weight is carried by thebraking wheels so that maximum braking may be obtained in either of theplanes rolling positions.

' Heretofore, when planes have been equipped withbrakes on the landingwheels, it has been necessary to place these wheels far forwardly of thecenter of the gravity of the plane so that the application of the brakeswould not nose the plane over. It can'be readily seen that theefficiency of these brakes were not high because the center of gravitybeing far rearwardly of the wheels, a large ortion of the weight of theplane was carried y the rear free wheel. The installation of a brake onthe rear wheel is very complicated or the like and still benefit by thestructure shown herein. r

Many advantages arise from my improved structure among which may bementioned that maximum braking of the plane may be obtained at all timeswithout the risk of damage to the plane. provides two rolling positionsfor the plane,

ing wheels. 7

Some changes may be made in the arrangement, construction, andcombination of the various parts of my improved device without departingfrom the spirit of my invention and it is my intention to cover by myclaims such changes as may reasonably be included within the scopethereof.

I claim as my invention:

1. In an airplane having a pair of landing wheels secured beneath itsintermediate portion, wheels secured a lesser distance beneath each endof 'said airplane, the center of gravity of the airplane being sopositioned that the airplane will be supported in stable equilibrium onthe landing wheels and rear and manually operable decelerating meanswhereby said center of gravity may be shifted to position forwardly ofsaid landing wheels to thereby rock the plane around the landing wheelsso as to be supported-by said landing wheels and forward wheel.

2. In an airplane having a pair of landing wheels disposed beneath itsintermediate portion, wheels secured a lesser distance beneath each endof-said airplane, said airplane having its center of gravity sopositioned that when the plane is rocked around the landing wheels saidcenter Will shift in the rocking plane from one side of the landingwheels to the other side, and brakes operating through said landingwheels whereby the center, of gravity may be operably shifted from oneof its positions to the other.

3. In an airplane of the high wing monoplane type, engines mounted uponthe upper surface of said wing whereby the center of Further, my landinggear in each of which the center of gravity of the plane issubstantially directly above the brakthe landing wheels the center ofgravity will .between said landing wheels and center of gravity so thatsaid center of gravity may be rocked forwardly and rearwardlyof thelanding wheels to provide two positions of stable equilibrium for saidairplane, and manually operable brakes on said landing wheels wherebysaid center of gravity may be shifted from one of said positions to theother.

4. An airplane having a pair of landing wheels disposed beneath itsintermediate portion, supporting means secured a lesser distance beneatheach end of said airplane, said airplane having its center of gravity sopositioned that when the plane is rocked around shift in the rockingplane from one side of the landing wheels to the other side, and brakesoperating through said landing Wheels whereby the center of gravity maybe operably shifted from one of its positions to the other position.

5. An airplane having a pair of landing wheels disposed beneath itsintermediate portion, a landing wheel secured a lesser distance beneaththe rear portion of said airplane, a skid secured a lesser distancebeneath the forward end of said airplane, the center of gravity of theairplane being so positioned that when the plane is rocked around thelanding wheels the center of gravity will shift in the rocking planefrom one side of the landing wheels to the other side, and brakesoperating through said landing wheels whereby the center of gravity maybe operably shifted from one of its positions to the other position.

6. An airplane having a pair of landing wheels secured beneath itsintermediate portion, supporting means secured a lesser distance beneatheach end of saidairplane the supporting means at the forward end of theplane comprising a skid secured directly to the bottom of the fuselage,and the center of gravity of the airplane being so. positioned that theairplane will be supported in stable equilibrium on the landing wheelsand rear support during normal taxiing of the plane,

and manually operable decelerating means I whereby said center ofgravity may be shifted to position forwardly ofsaid landing wheels tothereby rock the plane around thelanding wheels so as to be supported bythe landing wheels and said skid.

March 22, 1930.

HAROLD A. HICKS.

